The present invention relates to a cutting tool for machining a rotating workpiece, and more particularly to a multi-cornered reversible cutting plate which has a plurality of primary and secondary cutting edges of different lengths on its upper and lower sides.
A cutting plate is generally shaped as a nine-sided polygon which resembles an equilateral triangle with symmetrically distorted vertex regions that are formed by isosceles triangles, the base of each isosceles triangle being longer than its remaining sides. The primary cutting edges of the cutting plate are disposed in the regions of the isosceles triangles and are shorter than the secondary cutting edges. Such a reversible cutting plate can be used, for example, during initial machining work on the surfaces of circular rods, shafts, axles and pipes and can be made of high-speed steel and/or other hard metals.
Initial machining is frequently employed in the metal processing industry. Therefore, manufacturers and users of initial machining tools have endeavored to improve the quality of the products produced and to increase the economy of the initial machining process by suitable design of the cutting inserts used for the initial machining tool.
U.S. Pat. No. 3,621,549 discloses a nine-cornered reversible cutting plate of the general type described above. In the arrangement disclosed in the patent, the cutting tool is seated on a surface of an adapter member which in turn is seated on a surface of a tool holder. A chip breaker is mounted on top of the cutting tool and the adapter, cutting tool and chip breaker are secured to the tool holder by a tapered pin which exerts a downward camming force on the chip breaker.
However, this known cutting plate is not very well suited for initial machining because the edges available as the primary cutting edges, in conjunction with their angular positions, permit only a slight depth of cut. Moreover, during initial machining, the patented plate produces feed lines.